Power lawn mower and control mechanism therefor



w. l. SMITH 2,453,819 POWER LAWN IOWER AND CONTROL MECHANISM THEREFORNov. 16, 1948.

Filed Dec. 20, 1946 INVENTOR Ila meal Ju/rll ATTORNEYS 'may throw thedrive on Patented Nov. 16, 1948 POWER LAWN MOWER AND CONTROL MECHANISMTHEREFOR Wilfred I. Smith,

to Savage Arms Corp corporation of Deiawa Chicopee Falls, Mass.,assignor oration, Utica, N. Y., a re Application December 20, 1946,Serial No. 717,457

11 Claims. I

This invention relates to power driven lawn mowers and machines ofsimilar character and more particularly to the driving control for saidmachines.

The machines to which this invention is adapted are those which comprisea power driven tractor assembly guided by an operator walking behind themachine through the manipulation of a guiding handle.

An object of the invention is to provide a control means for the powerdrive whereby the operator by a foot pedal and may throw the drive off"'by depressing the guiding handle to a lower position. Except for thislowered position of the handle for throwing oif the drive, the handle isfree to be normally swung up and down in guiding the machine.

A further feature of improvement resides in a manually controlled stopwhich normally prevents the handle from beingswung too high in avertical direction, but which may be thrown out Of action by the footpedal and permit swinging of the handle to vertical position withrespect to the machine so that it may be conveniently stored or parkedin a relatively small space.

Further advantages and improvements will become apparent from thefollowing more detailed description taken in connection with theaccompanying drawing, in which:

Fig. 1 is a side elevation of a power driven lawn mower showing thedrive in on position;

Fig. 2 is a similar view showing the drive in "off position;

Fig. 3 is a detail plan of the associated parts; and

Fig. 4 is a fragmentary view showing the action of the parking hook inrelation to the guide handie.

foot pedal and For purposes of illustration the present invention isshown in its application to a power drive for a hand guided lawn mowermachine and only so much of the details of said lawn mower are hereinshown as are necessary for the understanding of the application of theinvention thereto.

' Referring to said drawing, the main frame of the lawn mower is of theusual construction and is constituted by side plates one of which isindicated at I, joined together by transverse tie rods 2 and 3, andhaving an upper fiat platform or deck 4 for support of the motor 5firmly fixed thereto. A bracket I riveted to the side plate I providesthe mounting for one end of the rear tie rod 3 as shown. The fronttraction wheels 6 for the machine are mounted in the frame as indicatedby the shaft at I, the near wheel not appearing on the drawing. A rearground roller 8 is also carried between the side plates of said frame inthe usual manner. A guiding handle for the machine comprises the usualbifurcated arms pivoted to the side plates of the frame and the lefthand branch of said handle is partially shown at 9 pivoted at III to theplate I.

The motor shaft II has fixed thereto the driving pulley I 2 and a jackshaft I3 has fixed thereto a driven pulley I4. The jack shaft I3 iscarried at the upper end of a rock frame I5 which is pivoted at It onthe deck of the main frame so that a swinging movement of said rockframe I5 will cause shaft I3 to approach or recede from the drive shaftII. A V belt I I connects said pulleys I2 and I4 for the transmission ofpower therebetween.

In the present embodiment the traction wheels 6 are driven from the reelshaft I8 by an internal gear drive as indicated in dotted lines at I9and 20. It will be understood that the reel shaft I8 carries the rotarycutter or reel (not shown) of the mower. The reel shaft also hasfastened thereto the large sprocket 2I which is driven through chain 22from sprocket 23 fixed to the jack shaft I3. It will be observed thatthe mounting of the jack shaft I3 on rock frame I5 is positioned that aslight swinging of said rock frame back and forth will not appreciablylengthen the distance between the jack shaft I3 and reel shaft I8whereby the tension on the driving chain 22 is not appreciably disturbedby said rocking movement. It will also be appreciated that when the rockframe I5 is swung clockwise it will "tighten the belt I I for a drivingcondition, and

that when swung anti-clockwise it will correspondingly loosen the beltfor a non-driving condition. In other words, the rock frame I5 serves asa belt tightener to throw the transmission on or off." frame serves toretain the belt I1 always in engagement with the grooves of pulleys l2and I4.

The present'invention provides for convenient means to render the drivefrom the motor 5 to the reel shaft I8 and the traction wheels 6operative or inoperative at the will of the operator 7 while the motorcontinues to run, and in the present embodiment this is accomplished byshifting the belt tightener above described. The shifting to on positionfor driving is brought about by the depression of a foot pedal, and theshifting to "off position for non-driving is made to occur only when theguiding handle is swung to its A suitable belt guide 31 fixed to themain and rearwardly to engage the This arrangement gives perthe operatorwho the handle at all lowermost position. feet control of the machine bymay thus keep a firm grip on times and also be able to swing the handlefreely up and down for guiding the machine. The mechanism for shiftingthe belt tightener to on and off positions will now be described.

The rock frame l5 has a rearwardly projecting arm 24 projectingrearwardly therefrom and on the outer end of which is pivotally hung alatch 25. This latch is shaped somewhat like an inverted T and has alower forward branch 26 and lower rear branch 21. The branch 26 isformed with a pair of seating recesses or notches 28, 29 adapted toengage with the tie rod 3 of the main frame which serves as a keeper forthe latch in retaining its position thereon.

When the said latch 25 is pressed downwardly and forwardly, the notch 28makes holding engagement with the keeper 3 and in so doing causes therock frame Hi to swing clockwise for a tight belt as clearly shown inFig. 1. When the latch is pressed down and to the rear from the positionshown in Fig. 1, the notch 29 makes holding engagement with the keeper 3and the rock frame I5 is swung anti-clockwise to provide a loose belt.The latch 25 is hung in such manner that it tends to be retained inwhatever position it may be set with respect to keeper 3 until it isforcibly shifted. The notch 28 of latch 25 may be termed the on" notchsince when engaged the drive is held in on position, and the notch 29may be termed the off notch, since its engagement signifies that thedrive is off. It will be appreciated that the tension of lbelt |1 tendsto swing rock frame |5 to non-drive position whenever the on notch 28 isreleased from its keeper 3.

The means for operating latch 25 in the manner described is preferablyin the form of a foot pedal lever 30 pivotally mounted on the tie rod 3adjacent the latch 25 and having a fiat treadle portion 3| at the rearend thereof, see Fig. 3 which overhangs the rearward lower arm 21 of thelatch 25. The forward end of lower arm 25 of said latch is also formedwith a horizontally turned lip 32 which lies in the path of the swin inghandle 9. A spring 36 mounted on the tie rod 3 as shown tends to keepthe rear treadle portion 3| in its upward position. A stop shoulder 33on the pedal lever 30 engages side plate I as shown to limit the upwardthrow. of said treadle 3|. The pedal lever 30 also has an integralforward extension in the form of a hook 34 which normally lies in thepath of a stop lug 35 carried by the handle 9 and which may be displacedtherefrom for a parking purpose as hereinafter described.

The operation of the control mechanism is as follows: Assuming the partsare as shown in Fig. 1 with the latch 25 in on position and the belt Hin driving condition; if the operator wishes to stop the drive he swingsthe handle 9 to its lowermost position whereby said handle will engageand press downwardly upon lip 32 on the forward end of latch 25 andshift the latter downwardly ofP notch 29 with its keeper or tie rod 3.This action will permit the rock frame |5 to swing slightly forward andloosen the belt H for the non-drive or off condition, as shown in Fig. 2of the drawing.

When the operator desires to shift to on" condition for driving, hesteps on the foot treadle 3| and depresses it far enough to throw thelatch 25 downwardly and forwardly for engaging its on notch 28 with saidkeeper or tie rod 3. This engaging movement of the latch 25 will pullthe rock frame l5 slightly to the rear and tighten the belt for thedriving condition shown in Fig. 1 and the parts will be retained in thisdriving condition by latch 25 until released by a manipulation of thehandle 9 to its lowermost position as previously described.

In the operation of guiding a lawn mower it is desirable to have a freeswinging handle as above described. But preferably the said handleshould be prevented from swinging too far upwardly so that it may beuseful as a brace in holding the machine from rolling backwards on anincline. For this purpose the forward end of the pedal lever 30 isprovided with its hook 34 which is normally in position to engage thelug 35 on the handle 9 as shown in solid lines in Fig. 4, and thus limitthe upward swinging of handle 9. On the other hand it is sometimesdesirable in parking or storing the machine in a narrow space to be ableto move the handle 9 into its vertical position with respect to themachine. For this purpose the hook 34 is formed so as to easily bemanipulated by the foot lever 3| and be moved to'dotted line position(Fig. 4) out of the path of the lug 35 on said handle 9. This will allowthehandle to be swung to its vertical position for parking.

What I claim is:

1. Control mechanism for the belt transmission of power driven lawnmovers and the like comprising in combination, a wheel supported mainframe, a guiding handle pivotally connected to said frame for freeswinging movement between up and down positions, said frame carryingthereon a motor and its drive shaft and also carrying a shaft for beingdriven thereby, a releasable driving connection between said motor shaftand driven shaft, means to shift said connection to operative conditionfor driving and to inoperative conditon for non-driving, a foot pedaloperable through said shifting means to shift said driving connectioninto its operative condition, said shifting means being operable by saidguiding handle to shift said driving connection to its inoperativecondition.

2. Control mechanism for the belt transmission of power driven lawnmowers and the like comprising in combination, a wheel supported mainframe, a guiding handle pivotally connected to said frame for freeswinging movement between up and down positions, said frame carryingthereon a motor and its drive shaft and also carrying a shaft for beingdriven thereby, a releasable driving connection between said shafts,means to shift said connection to operative condition for driving and toinoperative condition for non-driving, a foot pedal pivotally mounted onsaid main frame to operate said means to shift said driving connectioninto its operative condition, said shiftin means being positioned foroperation by said guiding handle only in the lowermost part of itsdownward movement to shift said driving connection to its inoperativecondition.

3. Control mechanism for the belt transmission of power driven lawnmowers and the'like comprising in combination, a wheel supported mainframe, a guiding handle pivotally connected to said frame for freeswinging movement between up and down positions, said frame carryingthereon a motor and its drive shaft and also carrying a driven shaftwith belt and pulley transmission bearcane tween said motor and drivenshafts, a belt tightener shiftable to "on" position wherein said belt istight for driving, and to o position wherein said belt is loose fornon-driving, a foot pedal and means operated thereby to shift said belttightener to its on" position, said means being operable by said guidinghandle to shift said belt tightener to its on position. v

4. Control mechanism for the belt transmission of power driven lawnmowers and the like comprising in combination, a wheel supported mainframe, a guiding handle pivotally connected to said frame for freeswinging movement between up and down positions, said frame carryingthereon a. motor and its drive shaft, and also carrying a driven shaftwith belt and pulley transmission between said motor and driven shafts,a belt tightener shit-table to on" position wherein said belt is tightfor driving, and to o position wherein said belt is loose fornon-driving, a foot pedal pivotally mounted on the main frame and meansoperated thereby to shift said belt tightener to its on" position, saidmeans being positioned for operation by said guiding handle only in thelowermost part of its downward movement to shift said belt tightener toits off position.

5. Control mechanism for the belt transmission of power driven lawnmowers and the like comprising in combination, a wheel supported mainframe, a guiding handle pivotally connected to said frame for freeswinging movement between said frame carrying thereon a motor and itsdrive shaft and also carrying a driven shaft with belt and pulleytransmission between said motor and driven shafts, a belt tightenershiftable to on position wherein said belt is tight for driving, and to"ofi position wherein said belt is loose for non-driving, a foot pedaland means operated thereby to shift said belt tightener to its onposition, said means being operable by said guiding handle to shift saidbelt tightener to its "01? position, said means including a keeper forretaining said belt tightener in position when shifted.

6. Control mechanism for the belt transmission of power driven lawnmowers and the like comprising in combination, a wheel supported mainframe, a guiding handle pivotally connected to said frame for freeswinging movement between up and down positions, said frame carryingthereon a motor and its drive shaft and also carrying a driven shaftwith belt and pulley transmission between said motor and driven shafts,a belt tightener shiftable to on position wherein said belt is tight fordriving, and to oif" position wherein said belt is loose fornon-driving, a foot pedal pivotally mounted on the main frame and meansoperated thereby to shift said belt tightener to its on" position, akeeper for retaining said belt tightener in its on position when shiftedthereto, said means being positioned for operation by said guidinghandle only in the lowermost part of its downward movement to releasesaid retaining means and shift said belt tightener to its off" position.

7. Control mechanism for the belt transmission of power driven lawnmowers and the like comprising in combination, a wheel supported mainframe, a guiding handle pivotally connected to said frame for freeswinging movement between up and down positions, said frame carryingthereon a motor and its drive shaft and also carrying a driven shaftwith belt and pulley transmission between said shafts, a belt tightenershiftable to and shift said belt tightener to oil "on" position whereinsaid belt is tight for driving, and to "oi!" position wherein said beltis loose for non-driving, latching means adapted when actuated to shiftsaid belt tightener into "on" position and to retain the same therein, afoot pedal arranged to thus actuate said latching means, said latchingmeans being operable by the guiding handle to release said latchingmeans position.

8. Control mechanism for the belt transmission of power driven lawnmowers and the like comprising in combination, a wheel supported mainframe, a guiding handle pivotally connected to said frame for freeswinging movement between I up and down positions, said frame carryingthereon position wherein said belt is tight for driving, and to "01!position wherein said belt is loose for non-driving, said belt tightenercomprising a rocking arm pivoted on said main frame and supporting oneend of said belt transmission, a foot p dal and means operated therebyto shift said belt tightener to its on position, said means beingoperable by said guiding handle to shift said belt tightener to its offposition.

10. Control mechanism for the belt transmission of power driven lawnmowers and the like comprising in combination, a wheel supported mainframe, a guiding handle pivotally connected to said frame for freeswinging movement between up and down positions, said frame carryingthereon a motor and its drive shaft and also carrying a driven shaftwith belt and pulley transmission between said shafts, a belt tightenershiftable to on position wherein said belt is tight for driving, and tooff position wherein said belt is loose for non-driving, said belttightener comprising a rocking arm pivoted on said main frame andcarrying one end of saidbelt transmission, a pivoted latch carried bysaid arm,

a keeper on said main frame for said latch, said latch adapted to swingsaid rocking am into on position when moved into holding engagementwithits keeper, a foot pedal operable to move said latch into saidholding engagement, and said latch being positioned for operation inghandle to release said latch from said holding engagement with itskeeper during the lowermost part of the downward movement of said handleand thereby allow said rocking arm toxswing to its "off" position.

11. Control mechanism for the 'belt transmisby said guidsion of powerdriven lawn mowers and the like comprising in combination, a wheelsupported main frame. a guiding handle pivotally connected to said framefor tree swingins movement between up and down positions. said framecarrying thereon a motor and its drive shaft and also carryinga drivenshaft with belt and pulley transmission between said aha-its, a belttishtener shittable to on" position wherein said belt is tight fordriving, and to "of!" position wherein said belt is loose fornon-driving, said belt tightener comprising a rocking arm pivoted onsaid main frame and carrylnl one end of said belt transmission, apivoted latch carried by said arm, a keeper on said main frame for saidlatch, said latch adapted to swing said rockinz arm into on positionwhen moved into holding engagement with its keeper, a foot pedaloperable to move said latch into said holding engagement, said latchbeing positioned for operation by said guiding handle to release saidlatch from the holding engagement with its keeper during the lowermostpart 0! the downward movement of said handle and thereby allow saidrocking arm to swing to its ofl position, an integral extension on saidi'oot pedal forming a hook and stop means on the guiding handleengageable by said hook for limiting the upward swinging movement ofsaid handle when said foot pedal is not depressed, the depression ofsaid foot pedal carrying its hook out of the path of the stop means onsaid handle whereby the latter may be raised to vertical position withrespect to said machine.

WHERE I. SMITH.

REFERENCES CITED The following references are of record in the ille ofthis patent:

UNITED STATES PATENTS Name Date Funk Mar. 21, 1939 Funk June 24, 1941Number

